Hypodermic syringe



A. E. SMITH sept. 21, 194s.

HYPDERHIC SYRINGE Filed nge. 51, 1946 (Ittomeg 'Jrmentor Pamesa sept. l,21, 194s autres' nrronenmc eramos'.

Arum E. smnn, La Ansel, cnn. Application December 81, 1946, Serial No. 119,860

s i chum. (ci. 12s-21s) l This 'invention relates to hypodermic syringes of a type which' are adapted to receive a drug carrying ampule; and it is an improvement on the device disclosed in Patent No. 2,377,274 heretofore issued to me on May 29, 1945.

In ampules for syringes, such as commonly distributed by manufacturers of pharmaceutical preparations, the drug to be injected is held suspended in a solvent. While such arrangementmay be found satisfactory in some cases, it is found that many drugs do not remain stable while held so suspended but undergo chemical changes, sufllcient to render the drug chemically inert or even toxic. When medicinal compounds undergo such chemical disintegration or form undesirable new compounds, they become unfit for hypodermic medication.

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It is, in view of the foregoing, the object of v the present invention to provide a hypodermic syringe which is adapted to receive a container within which the medicinal compound and the solvent for this compound are maintained completely separated from each other.

A further object is to provide a syringe within which the medical compound referred to may be admitted to the solvent by a simple manual manipulation of the syringe at the time the syringe is made ready for use.

More particularly, it is the object to provide, for insertion into a hypodermic syringe, an ampule within which provision is made for maintaining the two substances of the charge separated. A stil l further object is to provide a device in which. at the time the ampule is inserted into the syringe, by a simple additional manipulation thereof, a rearrangement of parts is effected tc cause the barrier between the drug and the solvent to -be removed so as to permit the two substances to combine.y

Another object is to provide a composite ampule st. ucture which is simple and inexpensive to manufacture and which is so constructed that the component parts thereof may be readily fitted together to fi m tightly separated compartments for the drug and the solvent.

These and other objects of the invention will be better understood from the following detailed vdescription and by referring to the accompanying drawings, of which:

Fig. 1 is a general view of a partly assembled device embodying the invention;

Fig. 2 is a cross sectional view of the composite ampule structure ofthe invention; Fig. 3 shows, on a larger scale, one of the component parts of the ampule; and' shown recessed at "i", I i to provide therein their `membranes lb, lib. In the process of manufac- 2 Fig. 4 is a view, partly in section, of the device of the invention as it appears during the injection manipulation thereof.

The type of syringe illustrated in the drawings is somewhat similar to lthe one disclosed inthe patent above referred to. It comprises a barrel I, in the front end of which is seated a tubular rearwardly pointed needle 2. On screw threads I. at the `front of the barrel is mounted a cap I, and the latter is perforated iittingly to receive the injection needle l.

The ampule of the invention consists of a tube B, which may be made of glass or of a suitable material which is not affected by water or any saline or acid solution, to the end that the solvent may be held stored therein for an indefinite period of time.

In this tube is seated a thimble-shaped insert 8, which may be made of the same material as 'the ampule and the rear end of which is closed by a plano-convex disc 9. As best shown in Fig. 3, the outer surface of this insert is slightly conical, and this shape is preferred partly because seating of the insert within the tube thereby is facilitated. Anotherreason for making the part corneal is that it is thereby rendered adaptable to be tightly seated within tubes of slightly varying diameter.

While it may be found sufficient to press the insert into the tube, it is preferred, in order to insure a fluid-tight seal, to apply to the outer surface of the insert a thermo-plastic solution such as glacial acetic acid or methylene dichloride commercially used slightly to soften and to combine plastic materials. When such softener is used, it is found that the insert will become tightly seated `and cannot be displaced.

As stated, the end wall 9 of the insert is preferably plano-convex, the inner surface thereof v being straight in order to afford maximum space therein, and it is vimportant to note that' the circular margin I0 of the end wall 9 is so thin and frangible that it may be readily fractured to break away this end wall, as wlil be described presently. `f

The insert forms a chamber within which the medicinal compound is placed in the f orm of a tablet A. or in granular or powder form as preferred, whereupon a compressible closure Ii is seated tightly to enclose the compound within the insert. A similar stopper I, is seated to close the other end of the tube. Preferably, these closuresare made from soft rubber and they are ture, a suitable' solvent is injected into the space Il through the membrane 9b in the conventional manner, and it is found that this membrane closes tightly upon completion of this operation. The ampule may then be stored and when required for use may be entered into the barrel I of the syringe.

The barrel of the syringe is internally threaded to receive a sleeve Il, within which a plunger il is axially slidable and this plunger .terminates in a head i8 of a size freely to enter the ampuie tube l. As this sleeve is seated in the barrel, it is found that it contacts the end of the partly inserted tube 5 and that it advances the latter until the membrane IIb of the closure Il reachesand rides over the pointed end of the needle 2. Fur'- v ther advance movement of the tube causes the end wall 9 to encounter the point of the needle and to be broken away from the insert along the margin I0, substantially as indicated in Fig. 4. The plunger Il may then be advanced to force the closure 9 ahead and thereby to inJect the ccntents of the istmpulev into the tissue of the patient through the needles 2 and l. I l

As indicated in Fig. 4, a spring I1 is* tightly seated on the plunger I5 to apply suillcient frictional pressure thereagainst to retain the plunger in any position of adjustment and thereby to facilitate manipulation of the syringe. In order to place-this spring within the sleeve, it becomes 30 necessary to make the latter in two parts, but when the part It* is tightly seated, it is found that the sleeve will function as an integral unit. For protection, when not in use, the needle 4 may be enclosed within a cover I9, which latter engages 35 screw threads Ib of the barrel.

ananas 4 A f It is seen from the foregoing that I have provided a simple and inexpensive syringe combination within which medicinal compounds may be safely stored over long periods of time and be made ready for use by a simple manipulation o! th sariiglge at the time injection isrequired.

An ampule for ahypodermic syringe comprising a. tube, a plastic thimble-shaped insert mounts able within' one endo! the tube to provide therein an open-end-chamber. the outer surface'of said insert being slightly conical to adapt the insert to variations in the' inner diameter of the tube. a plastic solvent i'or softening the outer surface of the insert to provide a duid-tight bond be tween the insert and thevinner wall of the tube. the bottom of theY insert margin, a soit compressible closure for said chamber, anda soft compressible closure for the opposite end of the tube.

- A ARTHUR E. SMITH.

REFERENCES CITED The following references are of record inv the 25 ille of this patent:

UNITED STATES PATENTS Number Name Date 1,259,964 Davis Mar. 19, 1918 1,607,561 Pittenger Nov. 16, 1926 1,718,593 Smith June 25, -1929 2,232,978 Smith r Feb. 25, 1941 2,323,159 Smith June 29, 1943 2,337,354 Smith Dec. 21, 1943 2,338,102 Fields Jan. 4, 1944 v2,345,301 Smith Mar.28, 1944 having a thin frangible' 

